The present disclosure relates to equipment for modifying the surface of an existing road, and in particular, to equipment for smoothing areas of existing pavement by removing bumps, upward projections, and other surface irregularities.
Road planning machines are used to remove bumps and other irregularities on the surface of a road, runway, taxiway, or other stretch of pavement. This planning effect is typically achieved by grinding the paved surface so that the grinding depth may vary slightly, but the surface produced by the grinding unit is more level than the original surface. The road planning machine typically includes a grinding unit that is powered by an engine or motor. A tractor is attached to, or integral with, the grinding unit for propelling the grinding unit against the paved surface in a desired direction.
One problem that exists in road planning machines is accurate control of the grinding unit and consistent grinding performed by the unit. This is especially true when it is desirable to produce the aforementioned planning effect by a tractor such as a skid steer loader having the grinding unit as an attachment. Any movement of the skid steer loader caused by, for example, crossing a bump or a recess in the paved surface, can affect the accuracy and quality of the planning effect. In other words, as a skid steer loader crosses a change in elevation in the paved surface, the rotary grinding unit is lifted or lowered by the degree of elevation change (or may even be rotated by a pitch angle) from the paved surface, thereby causing an uneven planning effect. In a similar fashion, as a skid steer loader crosses a change in lateral elevation in the paved surface, the rotary grinding unit is tilted to one side relative to the other by the degree of lateral elevation change (or may even be rotated by a roll angle) from the paved surface, thereby causing an uneven planning effect.
Thus, there remains a need for a pavement grinding apparatus designed to remove bumps and other irregularities from the surface of a road, runway, taxiway, or other pavement for a desired pavement profile. In particular, it would be desirable to obtain the desired pavement profile regardless of vertical or lateral elevation movement of the transporter relative to the grinding unit.